Why am I a great fake trader, but a bad real trader?

So I got my weekly email this morning from Marketocracy, the online paper-trading site. It’s a site where you can practice your trading by making fake trades with fake money. And after seeing my results, I can’t help ask myself “Why am I a great fake trader, but a bad real trader?”

My fake account is doing great considering the downward spiraling market that we’re in. But my real portfolio is stagnant. So, why is this? Why can I pick fake trades that return 6.79% for the past 7 days and beat the S&P 500 (4.31%), the NASDAQ (4.92%) and the Dow (4.25%)? But when I make real trades in my real portfolio they usually turn out to be crap?

Oh, and to make me feel even worse, my (fake) account returned 16.26% over the past 30 days and also beat the S&P (7.08%), NASDAQ (8.73% and Dow (6.20%). So, what do you think is going on inside my head when it comes to trading? I’d really like to hear your take on it.